<!DOCTYPE html>
<html>
<head>
<meta charset="UTF-8" />
<title>类的基本知识</title>
</head>
<body>
    <script type="text/javascript">
        function demo(){
            console.log(this);
        }
        demo();
        const x = demo.bind({a:1,b:2});
        x();

    </script>
</body>
</html>